Source: Brian Stelter / The New York Times After giving a nearly six-month tryout for the Internet talk show host Cenk Uygur, the cable news channel MSNBC is preparing to instead hand its 6 p.m. time slot to the Rev. Al Sharpton. Mr. Sharpton's imminent hiring, which was acknowledged by three people at the channel on condition of anonymity because the contract had not been signed, is significant in part because MSNBC and other news channels have been criticized for a paucity [...]